1. Field of the Invention
The present invention relates to a circuit of a node in a radio network and a method for transit time measurement between two nodes in a radio network.
2. Description of the Background Art
A radio network is defined in the industry standard IEEE 802.15.4-2006. On pages 21 to 23 of this standard, packets to be transmitted by radio are defined, which can contain different frames, such as a beacon frame, data frame, acknowledgment frame, or MAC command frame, for example.
Known from U.S. Pat. No. 5,220,332 is a range finding system with an interrogator and a transponder, which permits non-simultaneous measurements between two objects. A carrier signal is modulated with a (low-frequency) modulation signal having a variable modulation frequency in order to determine a distance between the interrogator and the transponder from the change in the modulation signal by means of a phase measurement or alternatively a transit time measurement.